000 AXNT20 KNHC 282336 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Oct 28 2021 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2335 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: A strong cold front moving across the eastern Gulf today is producing minimal gale force winds over the northern Gulf. Very active convection is along the front, and is also occurring within 60-120 nm ahead of it in a squall line, where frequent lightning and strong gusty winds prevail. Fresh to strong southerly winds will continue ahead of the front today as it moves into the Gulf coast of Florida. Winds and seas are expected to peak tonight. At this time, W to NW winds of 30-35 kt and seas in the 10-15 ft range are expected. These dangerous marine conditions will begin to gradually diminish from W to E late Fri into Sat. Please, see the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further details. ...TROPICAL WAVES... An Atlantic tropical wave is along 28W from 19N southward moving W at 10 to 15 kt. The main wave energy appears to be consolidating further to the east along 27W. Very active convection continues to the south and east of the wave, where satellite imagery shows scattered moderate convection from 04N to 08N between 23W and 30W. ...MONSOON TROUGH/ITCZ... The monsoon trough exits the Guinea coast near 10N14W and meanders westward to a 1011 mb low pressure near 09.5N33W to 06N41W. A segment of the ITCZ extends from 03N42W to the coast of Brazil near 02N50W. Numerous moderate to strong convection is seen from 04N to 11N between 10W and 24W. ...GULF OF MEXICO... A strong cold front extends from the central Florida Panhandle to the coast of Mexico near Veracruz, and is racing quickly SE across the basin this evening. Strong tstorms and squalls are occurring along and within 120 nm ahead of the front from the Florida coast near St. Pertersburg west to the Yucatan Channel into the Bay of Campeche. North of the front, drier conditions prevail. Gale force W to NW winds and large seas to 16 ft are occurring behind the front and N of 26N, while strong NW to N winds are elsewhere behind it. Scatterometer winds also suggest strong SW winds to 30 kt ahead of the front moving into the Florida Big Bend, where seas of 8-10 ft prevail. Please see the Special Features section for more details. The front is supported by a large area of low pressure shifting eastward across the eastern United States, producing a strong pressure gradient over the northern Gulf. This will support the strong to gale force winds across the northern Gulf waters behind the front through Fri. ...CARIBBEAN SEA... Generally fair and stable atmospheric conditions prevail across all but the southern Caribbean today. Scattered moderate isolated strong convection is noted along the coastal waters near Port of Spain in Venezuela and west along the Colombian coast. Morning scatterometer data showed moderate to fresh trade winds across the south central Caribbean between 65W and 72W, where peak seas were to 8 ft. Scatterometer data also showed fresh southerly winds opening up across the NW Caribbean and flowing through the Yucatan Channel and into the SE Gulf of Mexico, ahead of the cold front. Wind and seas are generally more tranquil across the remainder of the Caribbean today. Active convection across the SW Caribbean has diminished somewhat this morning. A weak ridge over the northern Caribbean Sea will continue to support gentle to moderate trade winds across the basin, with locally fresh winds possible in the Gulf of Honduras and off the coast of Venezuela. A cold front will enter the basin through the Yucatan Channel tonight. This front will move through the NW Caribbean into the weekend, before stalling from the Windward Passage to northern Nicaragua by Sun. Moderate to fresh NW winds and seas to 8 ft can be expected behind the cold front. ...ATLANTIC OCEAN... A cold front enters the discussion area near 31N57W to 27N63W where it begins to transition to a weakening stationary front to the northern Bahamas near 24N75W. Active convection continues along and within 90 nm southeast of both of these boundaries. Further west, a warm front extends into the western Atlantic from Georgia to 28N78W. Scattered moderate convection is mainly west 76W with this feature. Fresh to strong westerly winds are occurring behind the front, to the N of 29N and E of 70W, while fresh SW winds prevail southeast of the front and N of 24N to 60W. Seas are 6-11 ft in NW swell behind the front and 6-10 ft ahead of it. The remainder of the Atlantic is under the influence of a 1023 mb high pressure located near 30N27W. This system extends a ridge SW across the Greater Antilles. Light and variable winds are along the ridge axis while a belt of gentle to moderate trades is along the southern periphery of the ridge. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Ash cloud is slowly drifting SW. High volcanic ash concentration remains in the vicinity of the volcano. Marine and aviation interests should monitor this ongoing situation by reading the Volcanic Ash Advisory issued by Meteo- France, at http://vaac.meteo.fr/volcanoes/la-palma/. A cold front from around 31N59W through the central Bahamas will move east and gradually dissipate into the weekend. The next cold front will move off the SE U.S. coast tonight, then gradually reach a Bermuda to Windward Passage line over the weekend, before stalling. Strong winds and seas in excess of 8 ft are expected to develop on both sides of the front this evening into Sun, mainly N of 26N. $$ Torres